The changes to Radio 4's schedules are still bedding in and it does feel a bit lumpy at lunchtime to have two 15-minute programmes following the extended World at One.

But when one of the short programmes preceding the repeat of The Archers is as good as Stephen Fry on the Phone, you quickly adjust. This history of the mobile phone is intriguing, funny and well told by Fry (pictured), a famously early adopter of new technology.

Yesterday's opening programme was about the huge technical challenges in setting up a mobile network. In the 60s, we heard, the few mobile phones that existed contained a crystal in an oven for each channel they accessed. A full mobile system would involve hundreds of channels. As one engineer put it: "Are you going to have a tractor trailer trailing the user with all these ovens and crystals in it?"

The programme was full of it'll-never-catch-on warnings, surprises (a key pioneer chuckled as he admitted to Fry that he only got a mobile phone himself three years ago), and stubborn resistance to opening up the radio spectrum for mere phone calls. The engineers, frustrated by lack of progress, kept a sign in German above their desks. It read, Fry translated, "All art or planning is in vain when an angel relieves herself on your flintlock." Elisabeth Mahoney